Tissue damage by fatty acids released by lipolysis. Contribution to the pathogenesis of acute pancreatitis.

Local application of a mixture of emulsified olive oil and pancreatic lipase produces massive necrosis in liver, kidney, pancreas, skeletal muscle, and perivascular sheath within 3 hours with subsequent spread. The necrosis is accompanied by a marked leucocytic reaction and, - after 16-24 hours -, involves the walls of veins and arteries resembling the vascular necrosis of acute hemorrhagic pancreatitis. Electron microscopy shows necrosis of emigrated leucocytes after only 120 minutes. Vascular necrosis is not seen before the second day. The results clearly demonstrate the ability of free fatty acids to damage cells and tissue, and support the hypothesis that the morphological change of necrotizing pancreatitis are mainly produced by the release of fatty acids by active lipase.